Social, Psychological and Scientific Theory
The Origin of Species by means of natural selection
- Darwin addressed neither the origin of life nor how humans fit into the history of life on earth.
Rather, he proposed the theory of “natural selection,” a process by which species change into
new species over eons. Gradual change.
- He boldly claimed that, through this process, all life descended from a common ancestor that
lived millions of years ago.
Darwin’s 3 principles:
- Organisms produce offspring with different traits, which can be inherited.
- Organisms produce more offspring than can survive because the world has limited resources.
- Offspring whose traits are best suited to their environment survive and pass on those variations
to their offspring.
Correcting misconceptions about evolution
- Organisms do not progress from less evolved to more evolved. Humans and insects are equally
- Present-day humans are not evolved from present-day apes. Both evolved from a common
ancestor now extinct.
- Evolution is not random. While variations in inherited traits are random, natural selection is not.
Can be an accident of genetics. Enables a certain organism to thrive in an environment.
The Evolution of the Theory of Evolution:
Erasmus Darwin: belief that one species could gradually transform itself into a new one, a notion often
referred to as “transformism” (or “transmutation”).
Charles Lyell: believed that the Earth’s geologic history proceeded gradually, without sudden,
Thomas Malthus: argued that human populations grew faster than the available food supply, leading to
a struggle for resources.
Plants and animal species tend to live in certain climates.
Religious Reaction to Darwin:
- Positive and negative reactions.
- Darwin was the foundation for many modern scientific
- Was made fun of by religious sects.
- Becomes a vehicle with which we can question other theories.
Darwin Evolves: - “Evolved” Darwin’s final word. Only used once in the book.
- Darwin inserted the phrase about the “Creator” in the second edition
- “Evolution” was never used by him.
- 12 years after the origin of the species, Darwin publishes the descent of man and selection in
relation to sex.